1. Field of the invention
The present invention relates to a circuit housing, and, more specifically, to a housing for a circuit designed to be implanted in-vivo (i.e., an implantable circuit).
2. Discussion of the Background
There are several applications that require a circuit to be protected from the environment in which the circuit is intended to operate. For example, a human implantable glucose sensor circuit must be housed within a suitable housing to both protect the sensor from the human body and to protect the human body from the sensor. U.S. Pat. No. 6,330,464, the disclosure of which is incorporated herein by this reference, discloses such a sensor.
A housing encasing an implantable circuit should have at least some of the following characteristics: (1) the ability to protect the electronic circuitry of the sensor from the ambient in-vivo chemical and physical environment, (2) the ability to protect tissue adjacent to the sensor from any adverse reaction which could result as a consequence of contact (or leachables) from within the circuitry—in addition, beyond the adjacent tissue, the encasement must not permit leachables of any detectable significance into the general body environment; (3) the ability to permit wireless electronic communication between the circuitry and an external reader for power and signal; (4) the ability to permit free passage of wavelengths of light necessary for optical functioning of the sensor; (5) the ability to support the surface chemistry required to form a chemical recognition “front-end”; (6) the housing should be high volume manufacture-able; (7) the housing must be non-toxic and “biocompatible”; and (8) provide a sufficiently high reliability to meet the specifications of a medical product.